CLEVELAND, Ohio — Cuyahoga County Prosecutor Bill Mason, who built a powerful political machine over two decades and once had designs on higher office, announced Monday that he will take an early leave to work as a private-sector attorney.

Mason's latest four-year term doesn't expire until the end of the year, but he will step down Sept. 30 to become a partner in the Cleveland office of Columbus-based law firm Bricker & Eckler.

"I had envisioned when I laid out where I was going to go and what I was going to do that I would either be a U.S. senator or the governor of the state, and it just didn't happen," Mason said Monday during an interview in his Justice Center office. "It just didn't work out that way."

County Executive Edward FitzGerald is expected to appoint Timothy McGinty, the Democratic candidate for prosecutor, to replace Mason on an interim basis beginning Oct. 1, with affirmation coming later from the Cuyahoga County Democratic Party.

McGinty is running against independent Edward Wade in the election to be held Nov. 6.

Mason, 53, will be remembered as much for his political machine as for his bulldog approach to prosecution and his support of a reform movement that dramatically changed the face of local government.

His legacy also will be shaped, fairly or not, by a federal corruption probe that took down a rampant pay-for-play system across the county and put scores of elected officials, county employees and business contractors in prison.

The scandal never enveloped Mason or his office, but he was criticized for ignoring complaints of corruption in the Maple Heights School District years before several employees there pleaded guilty to bribery-related charges.

Mason dismissed the recent claims, saying Maple Heights officials confused discussions they had with him in 2001 with those they had with his predecessor, Stephanie Tubbs Jones, who died in 2008.

The corruption scandal helped propel a move to reform county government and Mason championed the change despite fierce opposition from many of his follow elected Democrats.

He helped draft a governing charter, approved by voters in 2009, that eliminated the three-commissioner model of leadership for one that has an elected county executive and county council. The charter also preserved the elected office of prosecutor.

View full sizeGus Chan, The Plain DealerBill Mason in his office at the Justice Center.

During Monday's interview, Mason said he recognized the need for government reform while a member of a task force trying to lure European wind-turbine manufacturers to the area. The experience convinced him that a solitary leader was needed to negotiate economic development deals.

As the county prosecutor, Mason had the reputation of being a relentless crime fighter. He proudly proclaims a 92 percent conviction rate, including plea bargains, compared with a national average of 68 percent.

"Everything I have ever seen Bill do as a prosecutor to prosecute hardcore criminals has been right on target in my mind," said Michael O'Shea, a Rocky River attorney who is also that suburb's prosecutor.

"He has to look in the faces of victims' family every day and say, 'This is what I've done for you to achieve justice,'" he said. "That's a tough thing to do, every day."

But others have accused Mason of piling on. A Plain Dealer investigation in 2010 concluded that Mason's office pursued hundreds of charges with little evidence and that judges dismissed a number of cases for that reason.

Mason said his office never indicted anybody without the evidence to back it up, but added, "Now, some things fall apart."

Attorney Wade, who is running for county prosecutor, said Mason's office has the habit of loading up charges on defendants in order to pressure them into plea deals.

Countered Mason: "That criticism has been around as long as prosecutors have been around. . . It's not accurate."

Defense lawyer Terry Gilbert, a longtime Mason nemesis, believes the prosecutor was unwilling to concede to mistakes and left more than one innocent defendant in jail while pursuing merit-less prosecutions.

Gilbert still smarts over his loss to Mason in what amounted to a re-trial of the infamous Sam Sheppard murder case. Sheppard was convicted of killing his wife in 1954, only to be acquitted of the same crime in 1966.

Three decades later, Sheppard's son, Sam Reese Sheppard unsuccessfully sued the county for false imprisonment of his father, who died in 1970. Mason, a newly appointed prosecutor, decided to work the case with Assistant County Prosecutor Steve Dever.

"I think he used that case to get name recognition and to help him get elected," Gilbert said.

The county Democratic Party appointed Mason in 1999 to fill the unexpired term of Tubbs Jones, who had been elected to Congress. Mason first won election to the prosecutor's office in 2000.

While Mason has made his share of enemies, he also has his supporters, including an unlikely one in Ian Friedman, former president of the Ohio Association of Criminal Defense Lawyers.

Friedman said Mason was a man of his convictions who was still willing to listen to the other side on important matters.

"At the end of the day," Friedman said, "he always ended up doing the right thing."

The two men once butted heads over the unwillingness of county prosecutors to turn over evidence to defense attorneys in a timely fashion.

When a change in state law required prosecutors to share evidence more promptly, Mason established an "electronic portal" that allows defense attorneys to get the evidence online. That move puts the county "leaps and bounds" ahead of the rest of the state, Friedman said.

Mason said he is most proud of his establishment of the Internet Crimes Against Children Task Force that is now cooperating with 320 law enforcement agency across the state to keep children from being exploited online.

"It's turned into something that I could never have imagined," he said.

Another highlight, he said, was the prosecution of investment broker Frank Gruttadauria. Mason's office used nearly $10 million forfeited by Gruttadauria's former employers to pay for technology upgrades in the prosecutor's office and throughout the courthouse. He also used the money to create a crime lab that is to be built at the county medical examiner's office.

Steve Dever, who was Mason's chief trial attorney for 12 years, gives Mason high marks for instituting the state's first community-based prosecution program that targets and identifies criminal activity at the neighborhood level.

The first such program was established in East Cleveland, he said, with prosecutors meeting regularly with neighborhood watch groups.

But perhaps more than anything, Dever will remember Mason as being cool under pressure.

"Even in the most stressful times he's been able to endure," Dever said.

But Mason, the prosecutor, was only half the man. A former Parma councilman and law director, he rose to political power at the same time as former county Commissioner Jimmy Dimora.

A fellow Democrat, Dimora used a charismatic personality to become one of the county's most powerful politicians and the party's county chairman, only to succumb to greed and end up in prison, convicted of racketeering.

The more deliberate Mason built his own Parma-based machine by campaigning aggressively and helping other ambitious politicians get elected to suburban and countywide offices.

A Plain Dealer investigation in March of 2010 determined that nearly one in five people he had hired since becoming prosecutor either held public office or was related to or friends with other politicians.

Mason made no apologies for the connections, stating at the time that the prosecutor's office had long been a proving ground for future politicians, judges and community leaders.

But his clout began to decline after announcing in 2010 that he would not seek a second term. When he tried to get the local Democratic Party's executive committee to nominate his top assistant, Michael O'Malley, for a Juvenile Court seat, the party leaders picked another candidate.

On Monday, Mason acknowledged feeling like a lame-duck. He also addressed the some of the controversy surrounding his last term as prosecutor.

"Certainly over the last two years I got banged around pretty good, but that had nothing to do with my decision not to stay in the game," he said.

At Bricker & Eckler, Mason said, he will build a civil practice at representing public sector clients, such as counties and school boards, and that he also will stay involved in politics as a Democratic activist.

O'Shea, the Rocky River prosecutor, said Mason should not be judged by the number of detractors. Tubbs Jones had her critics, O'Shea said, while legendary prosecutor John T. Corrigan had double Mason's foes. Yet both were great prosecutors.

"It's a complaint-ridden business," O'Shea said. "It's worse than being a waiter or a matre d' at a restaurant."